position
Where the resource is at this instant, which is not the same thing as currentLocation.
currentLocation is where it last arrived, and it is what every existing verb sets and reads; this is where it is now. The two agree except during a journey made through the seam over a spatial model that can interpolate, and there this one is the live answer. Nothing that existed before reads this, and it does not replace anything: a distance-based dispatching rule should read it, and a model that asks where a resource is in the ordinary sense should keep asking currentLocation.